1. Field of the Invention
This invention relates to a posturized foam ply for use in a bedding or seating product, and more particularly, to such a foam ply which selectively incorporates latex in order to provide the foam ply with different degrees of firmness.
2. Description of the Related Art
Foam pads for use in bedding or seating products are known. These foam pads commonly are made of an open-cell polyurethane foam and extend across the entire width and length of the particular bedding or seating product. If the particular bedding or seating product is a mattress, typically one such foam pad is placed on one side of the mattress core, and a second foam pad is placed on the opposite side of the mattress core, thereby effectively xe2x80x9csandwichingxe2x80x9d the mattress core. This combination then typically is covered with an upholstered fabric covering.
Some foam pads have been designed so as to provide multiple degrees of stiffness or firmness. In particular, in a bedding structure which includes an innerspring mattress and a padded cover, the padded cover includes a sheet of convoluted foam which covers essentially the full length of the mattress. The sheet of convoluted foam is stiffened over the middle part of the mattress length by a complementary piece of convoluted foam which is mated with the initial sheet. While the complementary piece may assist in providing an area of increased stiffness, this additional piece results in added thickness to that particular area of the padded cover, which may prove uncomfortable to a user.
Another mattress has an upholstery topper layer having a firming edge about its perimeter. In further detail, the topper layer has a foam layer and a firming edge which is attached to the perimeter of the foam layer using glue or the like, with the firming edge being made of a material which is more firm than the foam layer. While this particular topper layer may provide edge support for a mattress, multiple types of foam or other material must be provided and subsequently attached, in order to provide a single ply.
The above-mentioned drawbacks and limitations have been overcome by a posturized foam ply for use in a bedding or seating product, in which the foam ply has a first section which includes latex, and a second section which is free of latex, thereby providing the foam ply with different degrees of firmness. With the selected application of latex to a single foam ply, a posturized foam ply product may be achieved without the need for either a convoluted foam surface or multiple blocks or pieces of foam being glued or otherwise attached to one another.
The invention also is directed to a posturized bedding or seating product, in which the product has a core, an upholstered covering, and a posturized foam ply. In further detail, the core has a first surface and an oppositely-disposed second surface, and the upholstered covering covers at least one of the core first and second surfaces. The foam ply, itself, is positioned between the core and the upholstered covering, with the foam ply having a first section which includes latex and a second section which is free of latex, thereby providing the foam ply with different degrees of firmness.
In addition, the invention is directed to a method of making a posturized foam ply for use in a bedding or seating product. In this aspect of the invention, the foam ply has a first surface, an oppositely-disposed second surface, an interior between the first and second surfaces, and a depth which extends from the first surface to the second surface. The method, itself, includes the steps of: applying latex to a first section of one of the first and second surfaces, while maintaining a second section of the one of the first and second surfaces free of latex; moving at least some of the latex from the first section into the interior; and curing the latex, thereby forming a foam ply with different degrees of firmness.